Preparing food products in a pouch is generally desirable. It permits the food product to be hygienically handled without direct contact with the food and it typically reduces or eliminates the need for cleaning cooking utensils. For example, it is known to boil a variety of foods including rice and pastas in net pouches. In doing so, the net pouch with rice or pasta is immersed into boiling water. After the food is cooked, the pouch is lifted out of the water. The pouch then acts as its own colander as the water drains from the food and out of the pouch through the spaces in the net.
The pouches described above are typically not used for certain types of food like vegetables or fish because cooking these types of food directly in water can result in the loss of vitamins and color from the food. The uptake of water can also result in a change in the structure of the product as well as in the product's overall flavor.
In response to the drawbacks caused by the direct exposure of certain foods to water during the cooking process, the “boil-in-bag” process has been developed. A boil-in-bag is a closed pouch which prevents contact between the food contained in the bag and the water along with the loss of vitamins and color described above. Moreover, boil-in-bag meals are often previously prepared cooked dishes in sauce which makes them unsuitable for being placed directly into water without any protective package. Such bags are very difficult to handle after boiling because the heat imparted due to the boiling is retained within the bag and may cause burns or other injury to the consumer when the bag is opened to access the food.
In response to the drawbacks of the boil-in-bag process described above, various types of disposable containers have been developed for use in heating or cooking foods in microwave ovens. For example, U.S. Pat. No. 4,961,944 to Matoba et al discloses a flexible pouch for use in cooking frozen foods. The food is filled into the pouch which is sealed and then frozen. The pouch has a number of holes covered by an adhesive strip. The adhesive strip is removed before microwaving to provide a vent for steam which is generated during the microwave cooking process.
Plastic containers having lids with pressure relief valves are also known such as disclosed in PCT Application PCT/CH98/00546. This application discloses use of a container having a tray and rigid cover. The cover has a pressure relief valve which opens and closes to maintain a predetermined pressure range for pressure cooking for fresh food in the container headed by a microwave. However, such packaging is relatively expensive and the shelf life for fresh foods is relatively short.
In view of the foregoing, there is a need for a low cost, low waste article and method of steaming frozen food products without encountering the drawbacks inherent in the prior art.